Fungicidal mixtures

ABSTRACT

A fungicidal mixture containing a) the oxime ether carboxamide of the formula I  &lt;IMAGE&gt;  and b) 1-(2-cyano-2-methoxyiminoacetyl)-3-ethylurea (II) H3CCH2-NHCONHCO-C(CN)=NOCH3 in a synergistically active amount is described.

The present invention relates to a fungicidal mixture which contains

a) the oxime ether carboxamide of the formula I ##STR2## and b)1-(2-cyano-2-methoxyiminoacetyl)-3-ethylurea (II)

    H.sub.3 CCH.sub.2 -NHCONHCO-C(CN)═NOCH.sub.3

in a synergistically active amount.

The invention additionally relates to processes for controlling harmfulfungi using mixtures of the compounds I and II and the use of thecompound I and the compound II for the production of mixtures of thistype.

The compound of the formula I, its preparation and its action againstharmful fungi are disclosed in the literature (EP-A 477 631). Thecompound II (U.S. Pat. No. 3,957,847; common name: cymoxanil), itspreparation and its action against harmful fungi are likewise known.

With respect to a decrease in the application rates and an improvementof the spectrum of action of the known compounds, the present inventionis based on mixtures which, with a reduced total amount of appliedactive compounds, have an improved action against harmful fungi(synergistic mixtures).

Accordingly, the mixture defined at the beginning has been found. It hasadditionally been found that on simultaneous joint or separateapplication of the compound I and the compound II or on application ofthe compound I and the compound II succession harmful fungi can becontrolled better than with the individual compounds.

The compounds of the formulae I and II can be present in the E or the Zconfiguration with respect to the C═N double bond (with respect to thecarboxylic acid function group). Accordingly, they can be used in themixture according to the invention in each case either as the pure E orZ isomer or as an E/Z isomer mixture. The E/Z isomer mixture or the Eisomer is preferably used in each case, the E isomer being particularlypreferred in the case of the compound I.

Because of the basic character of the NH group, the compound I and thecompound II are able to form salts or adducts with inorganic or organicacids or with metal ions.

Examples of inorganic acids are hydrohalic acids such as hydrofluoricacid, hydrochloric acid, hydrobromic acid and hydriodic acid, sulfuricacid, phosphoric acid and nitric acid.

Suitable organic acids are, for example, formic acid, carbonic acid andalkanoic acids such as acetic acid, trifluoroacetic acid,trichloroacetic acid and propionic acid and also glycolic acid,thiocyanic acid, lactic acid, succinic acid, citric acid, benzoic acid,cinnamic acid, oxalic acid, alkylsulfonic acids (sulfonic acids havingstraight-chain or branched alkyl radicals having 1 to 20 carbon atoms),arylsulfonic acids or -disulfonic acids (aromatic radicals such asphenyl and naphthyl which carry one or two sulfonic acid groups),alkylphosphonic acids (phosphonic acids having straight-chain orbranched alkyl radicals having 1 to 20 carbon atoms), arylphosphonicacids or -diphosphonic acids (aromatic radicals such as phenyl andnaphthyl which carry one or two phosphoric acid radicals), the alkyl andaryl radicals being able to carry further substituents, eg.p-toluenesulfonic acid, salicylic acid, p-aminosalicylic acid,2-phenoxybenzoic acid, 2-acetoxybenzoic acid etc.

Suitable metal ions are in particular the ions of the elements of thesecond main group, in particular calcium and magnesium, of the third andfourth main group, in particular aluminum, tin and lead, as well as ofthe first to eighth subgroup, in particular chromium, manganese, iron,cobalt, nickel, copper, zinc and others. The metal ions of the elementsof the subgroups of the fourth period are particularly preferred. Themetals can in this case be present in the different valencies applicableto them. Preferably, the pure active compounds I and II are employed inthe preparation of the mixtures, to which, if required, further activecompounds against harmful fungi or other pests such as insects,arachnids or nematodes, or alternatively herbicidal or growth-regulatingactive compounds or fertilizers, can be admixed.

The mixtures of the compounds I and II and the simultaneous joint orseparate use of the compounds I and II are distinguished by anoutstanding action against a wide spectrum of phytopathogenic fungi, inparticular from the Ascomycetes and Basidiomycetes class. In some casesthey are systemically active and can therefore also be employed asfoliar and soil fungicides.

They have particular importance for the control of a multiplicity offungi on various crop plants such as cotton, vegetable plants (eg.cucumbers, beans and cucurbits), barley, grass, oats, coffee, maize,fruit plants, rice, rye, soybean, grape, wheat, decorative plants, sugarcane and a multiplicity of seeds.

In particular, they are suitable for the control of the followingphytopathogenic fungi: Erysiphe graminis (powdery mildew) on cereals,Erysiphe cichoracearum and Sphaerotheca fuliginea on cucurbits,Podosphaera leucotricha on apples, Puccinia species on cereals,Rhizoctonia species on cotton and lawns, Ustilago species on cereals andsugar cane, Venturia inaequalis (scab) on apples, Helminthosporiumspecies on cereals, Septoria nodorum on wheat, Botrytis cinerea (graymold) on strawberries and vines, Cercospora arachidicola on groundnuts,Pseudocercosporella herpotrichoides on wheat and barley, Pyriculariaoryzae on rice, Phytophthora infestans on potatoes and tomatoes,Plasmopara viticola on vines, Alternaria species on vegetables and fruitand also Fusarium and Verticillium species.

They are additionally applicable in the protection of materials (eg.wood preservation), for example against Paecilomyces variotii.

The compounds I and II can be applied simultaneously jointly orseparately, or succession, the sequence in the case of separateapplication in general having no effect on the control success.

The compounds I and II are customarily applied in a weight ratio of from10:1 to 0.1:1, preferably from 5:1 to 0.2:1, in particular from 5:1 to1:1.

Depending on the type of effect desired, the application rates of themixtures according to the invention are from 0.01 to 3 kg/ha, preferablyfrom 0.1 to 1.5 kg/ha, in particular from 0.1 to 1.0 kg/ha. Theapplication rates here for the compound I are from 0.01 to 0.5 kg/ha,preferably from 0.05 to 0.5 kg/ha, in particular from 0.05 to 0.4 kg/ha.The application rates for the compound II are correspondingly from 0.01to 0.5 kg/ha, preferably from 0.05 to 0.5 kg/ha, in particular from 0.05to 0.4 kg/ha.

In the treatment of seed, application rates of mixture of from 0.001 to50 g/kg of seed, preferably from 0.01 to 10 g/kg, in particular from0.01 to 8 g/kg, are in general used.

If harmful fungi which are pathogenic for plants are to be controlled,the separate or joint application of the compounds I and II or of themixtures of the compounds I and II is carried out by spraying or dustingthe seeds, the plants or the soils before or after sowing of the plantsor before or after emergence of the plants.

The fungicidal synergistic mixtures and the compounds I and II accordingto the invention can be prepared, for example, in the form of directlysprayable solutions, powder and suspensions or in the form ofhigh-percentage aqueous, oily or other suspensions, dispersions,emulsions, oil dispersions, pastes, dusting compositions, broadcastingcompositions or granules and applied by spraying, atomizing, dusting,broadcasting or watering. The application form is dependent on theintended use; it should in each case guarantee a dispersion of themixture according to the invention which is as fine and uniform aspossible.

The formulations are prepared in a manner known per se, eg. by additionof solvents and/or carriers. Inert additives such as emulsifiers ordispersants are customarily admixed to the formulations.

Suitable surface-active substances are the alkali metal, alkaline earthmetal or ammonium salts of aromatic sulfonic acids, eg. lignosulfonicacid, phenolsulfonic acid, naphthalenesulfonic acid anddibutylnaphthalenesulfonic acid, as well as of fatty acids, alkyl- andalkylarylsulfonates, alkyl-, lauryl ether and fatty alcohol sulfates,and also salts of sulfated hexa-, hepta- and octadecanols or fattyalcohol glycol ethers, condensation products of sulfonated naphthaleneand its derivatives with formaldehyde, condensation products ofnaphthalene or of naphthalenesulfonic acids with phenol andformaldehyde, polyoxyethylene octylphenol ethers, ethoxylated isooctyl-,octyl- or nonylphenol, alkylphenol or tributylphenyl polyglycol ethers,alkylaryl polyether alcohols, isotridecyl alcohol, fattyalcohol-ethylene oxide condensates, ethoxylated castor oil,polyoxyethylene or polyoxypropylene alkyl ethers, lauryl alcoholpolyglycol ether acetate, sorbitol esters, lignin-sulfite waste liquorsor methylcellulose. Powder, broadcasting and dusting compositions can beprepared by mixing or joint grinding of the compound I or II or themixture of the compounds I and II with a solid carrier.

Granules (eg. coated, impregnated or homogeneous granules) arecustomarily prepared by binding the active compound or the activecompounds to a solid carrier.

Fillers or solid carriers used are, for example, mineral earths such assilica gel, silicic acids, silicates, talc, kaolin, limestone, lime,chalk, bole, loess, clay, dolomite, diatomaceous earth, calcium andmagnesium sulfate, magnesium oxide, ground plastics, and fertilizerssuch as ammonium sulfate, ammonium phosphate, ammonium nitrate, ureasand vegetable products such as cereal flour, tree bark meal, wood mealand nutshell meal, cellulose powder or other solid carriers.

The formulations in general contain from 0.1 to 95% by weight,preferably from 0.5 to 90% by weight, of one of the compounds I and IIor of the mixture of the compounds I and II. The active compounds are inthis case employed in a purity of from 90% to 100%, preferably from 95%to 100% (according to NMR spectrum or HPLC).

The compound I or II and the mixtures or the corresponding formulationsare applied by treating the harmful fungi or the plants, seeds, soils,surfaces, materials or spaces to be kept free from them with afungicidally active amount of the mixture, or of the compounds I and IIin the case of separate application. Application can be carried outbefore or after attack by the harmful fungi.

Examples of the synergistic action of the mixtures according to theinvention against harmful fungi.

It was possible to show the fungicidal action of the compound and of themixtures by the following tests:

The active compounds were prepared separately or jointly as a 20%strength emulsion in a mixture of 70% by weight of cyclohexanone, 20% byweight of Nekanil® LN (Lutensol® AP6, wetting agent having emulsifierand dispersant action based on ethoxylated alkylphenols) and 10% byweight of Emulphor® EL (Emulan® EL, emulsifier based on ethoxylatedfatty alcohols) and accordingly diluted to the desired concentrationwith water.

Assessment followed determination of the attacked leaf areas in percent.These percentage values were converted into degrees of action. Thedegrees of action of the active compound mixtures to be expected weredetermined according to the Colby formula [R. S. Colby, Weeds 15, (1967)20-22] and compared with the degrees of action observed.

Colby formula:

    E=x+y-x×y/100

E is the degree of action to be expected, expressed in % of theuntreated control, when using the mixture of the active compounds A andB in the concentrations a and b

x is the degree of action, expressed in % of the untreated control, whenusing the active compound A in the concentration a

y is the degree of action, expressed in % of the untreated control, whenusing the active compound B in the concentration b

At a degree of action of 0, the attack of the treated plants correspondsto that of the untreated control plants; at a degree of action of 100the treated plants showed no attack.

Activity against vine Peronospora

Leaves of potted vines of the variety Muller-Thurgau were sprayed withaqueous spray liquor which contained 80% of active compound and 20%emulsifier in the dry matter. In order to be able to assess the durationof action of the active compounds, the plants were placed in agreenhouse for 8 days after drying on of the spray coating. Only thenwere the leaves infected with a zoospore suspension of Plasmoparaviticola (vine Peronospora). The vines were then first placed for 48hours in a water vapor-saturated chamber at 24° C. and then for 5 daysin a greenhouse at from 20° to 30° C. After this time, the plants wereplaced in the moist chamber again for 16 hours to accelerate escape fromthe sporangiophore. Assessment of the extent of fungal outbreak on thebottoms of the leaves was then carried out.

    ______________________________________                                                    Active compound con-                                                                         Degree of action in                                            centration in the                                                                            % of the untreated                                 Active compound                                                                           spray liquor in ppm                                                                          control                                            ______________________________________                                        Control (untreated)                                                                       --             0                                                  I.          16             87                                                              2             0                                                  II.         16             0                                                               2             0                                                  ______________________________________                                        Mixture according                                                                         degree of action                                                                             degree of action                                   to the invention                                                                          observed       calculated*)                                       ______________________________________                                        I + II 16 + 16                                                                              93.5         87                                                 1:1 mixture                                                                   I + II 2 + 2                                                                                35.5         0                                                  1:1 mixture                                                                   ______________________________________                                         *) calculated by the Colby formula                                       

From the results of the test it emerges that the degree of actionobserved in all mixture ratios is higher than the degree of actionforecast by the Colby formula.

We claim:
 1. A composition comprising a fungicidally effective amount ofa fungicidal mixture containinga) the oxime ether carboxamide of theformula I ##STR3## and b) 1-(2-cyano-2-methoxyiminoacetyl)-3-ethylurea

    H.sub.3 CCH.sub.2 -NHCONHCO-C(CN)═NOCH.sub.3           (II)

in a synergistically active amount, wherein the weight ratio of thecompound I to the compound II is about 1:1.
 2. A process for controllingharmful fungi, which comprises treating the harmful fungi, theirenvironment or the plants, seeds, soils, surfaces, materials or spacesto be kept free from them with a synergistic fungicidally effectiveamount of a composition comprisinga) the oxime ether carboxamide of theformula I ##STR4## b) 1-(2-cyano-2-methoxyiminoacetyl)-3-ethylurea

    H.sub.3 CCH.sub.2 -NHCONHCO-C(CN)═NOCH.sub.3           (II)

in a synergistically active amount, wherein the weight ratio of thecompound I to the compound II is from 1:1.
 3. The process as claimed inclaim 2, wherein the composition is applied simultaneously jointly orseparately, or successively.
 4. The process as claimed in claim 2,wherein the harmful fungi, their environment or the plants, seeds,soils, surfaces, materials or spaces to be kept free from them aretreated with from 0.01 to 0.5 kg/ha of the compound I.